A Randomized, Double-Blind, Placebo-Controlled Study to Evaluate the Efficacy of Tenapanor as Adjunctive Therapy to Phosphate Binder Therapy in End-Stage Renal Disease (ESRD) Subjects With Hyperphosphatemia
Trial Snapshot
- Phase
- Phase 2
- Status
- Completed
- Sponsor
- Ardelyx
- Enrollment
- 236
- Locations
- 48
- Primary Endpoint
- Change in Serum Phosphorus (s-P) Level From Baseline to Week 4.
Study Overview
Brief Summary
This is a randomized, double-blind, placebo-controlled study to evaluate the effect of tenapanor on change in s-P levels when tenapanor is administered orally, twice daily for 28 days as adjunctive therapy to ESRD subjects with hyperphosphatemia on stable phosphate binder therapy.
Detailed Description
The study consists of a Screening visit; a Run-in Period of at least 2 weeks and up to 4 weeks, where existing phosphate binder treatment is maintained; and a 4-week Double-Blind Treatment Period.
At Screening, a subject must be on thrice daily phosphate binder therapy and have a serum phosphate (s-P) level ≥5.5 and ≤10.0 mg/dL to qualify for entering the study. s-P will be measured at each visit during the run-in period to enable the evaluation of the s-P randomization criteria.
Subjects who qualify to enroll in the study will be randomized in a 1:1 ratio to receive tenapanor or placebo while continuing their existing phosphate binder treatment.
During the Double-Blind Treatment Period, subjects will receive tenapanor or placebo starting at a dose of 30 mg bid
Study Design
- Study Type
- Interventional
- Allocation
- Randomized
- Intervention Model
- Parallel
- Primary Purpose
- Treatment
- Masking
- Triple (Participant, Care Provider, Investigator)
Eligibility Criteria
- Ages
- 18 Years to 80 Years (Adult, Older Adult)
- Sex
- All
- Accepts Healthy Volunteers
- No
Inclusion Criteria
- •Signed and dated informed consent prior to any study specific procedures.
- •Males or females aged 18 to 80 years, inclusive, at Screening
- •Females must be non-pregnant, non-lactating and either be post-menopausal for at least -2 months, have documentation of irreversible surgical sterilization, use of acceptable -contraceptive method, or sexual abstinence, or a sterile sexual partner from Screening -until 30 days after the last subject visit.
- •Males must agree to avoid fathering a child (or donating sperm), and therefore be either sterile (documented) or agree to use approved methods of contraception, from the time of enrollment until 30 days after end of study.
- •Chronic maintenance hemodialysis (HD) 3x/week for at least 3 months or chronic maintenance peritoneal dialysis (PD) for a minimum of 6 months.
- •If receiving active vitamin D or calcimimetics, the dose should have been unchanged for the last 4 weeks prior to Screening.
- •Kt/V ≥1.2 at most recent measurement prior to Screening.
- •Prescribed and taking phosphate binder medication at least 3 times per day, and the prescribed dose should have been unchanged during the last 4 weeks prior to Screening.
- •Serum phosphorus levels must be ≥5.5 and ≤10.0 mg/dL at Screening and the end of the run-in period, analyzed at the central laboratory used in the study.
Exclusion Criteria
- •Severe hyperphosphatemia defined as having an s-P level >10.0 mg/dL on phosphate-binders at any time point during routine clinical monitoring for the 3 preceding months before Screening.
- •Serum/plasma parathyroid hormone >1200 pg/mL.
- •Clinical signs of hypovolemia at Screening as judged by the Investigator.
- •History of inflammatory bowel disease (IBD) or irritable bowel syndrome with diarrhea (IBS-D).
- •Scheduled for living donor kidney transplant or plans to relocate to another center during the study period.
- •Use of an investigational agent within 30 days prior to Screening.
- •Involvement in the planning and/or conduct of the study (applies to both Ardelyx/Contract Research Organization (CRO) staff and/or staff at the study site).
- •If, in the opinion of the Investigator, the subject is unable or unwilling to fulfill the requirements of the protocol or has a condition which would render the results uninterpretable.
Arms & Interventions
Tenapanor 30 mg BID
During the Double-Blind Treatment Period, subjects will receive tenapanor starting at a dose of 30 mg bid (three 10 mg tablets each time).
Investigators may decrease or increase the dose of study medication based on s-P levels and/or gastrointestinal (GI) tolerability in 10 mg increments to a minimum of 10 mg bid or a maximum of 30 mg bid at any time during the Double-Blind Treatment Period.
Intervention: Tenapanor (Drug)
Tenapanor 30 mg BID
During the Double-Blind Treatment Period, subjects will receive tenapanor starting at a dose of 30 mg bid (three 10 mg tablets each time).
Investigators may decrease or increase the dose of study medication based on s-P levels and/or gastrointestinal (GI) tolerability in 10 mg increments to a minimum of 10 mg bid or a maximum of 30 mg bid at any time during the Double-Blind Treatment Period.
Intervention: Phosphate Binder Agents (Drug)
Placebo
same size, weight and appearance of experimental drug
Intervention: Placebo (Drug)
Placebo
same size, weight and appearance of experimental drug
Intervention: Phosphate Binder Agents (Drug)
Outcomes
Primary Outcomes
Change in Serum Phosphorus (s-P) Level From Baseline to Week 4.
Time Frame: 4 Weeks (28 days randomization period; from baseline to week 4)
Difference in mean change from baseline in s-P level at Week 4 between the tenapanor and placebo groups.
Secondary Outcomes
- Relative Change From Baseline in cFGF23 at Week 4(4 Weeks (28 days randomization period))
- s-P Response at Week 4(4 Weeks (28 days randomization period))
- Relative Change From Baseline in iFGF23 at Week 4(4 Weeks (28 days randomization period))